From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 969C3C19F29 for ; Mon, 1 Aug 2022 11:49:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230292AbiHALts (ORCPT ); Mon, 1 Aug 2022 07:49:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35144 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231708AbiHALtL (ORCPT ); Mon, 1 Aug 2022 07:49:11 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B8A83F31C; Mon, 1 Aug 2022 04:48:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EF95661210; Mon, 1 Aug 2022 11:48:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04D9EC433D6; Mon, 1 Aug 2022 11:48:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1659354520; bh=jSo4xF4m8OnK0v74bY7eInmtx1SwCGLzwrI1ExsX8p0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vhWdgH3IrIAPpQWphhXM8vRxLJlXKbidAIoPLQ3E2xrt09su+ZhuT/6mYkXPx236I nILjyF/xS7hXW0Uu/dEVQlH0t6xrfDoj3MYxKuyaiAR7x0YxPEq7sXC5epLmGRPI7r i1JKnDXaJX4HACpJxaeK3GH889Twn4HJfo9hMkq4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuniyuki Iwashima , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 24/34] tcp: Fix a data-race around sysctl_tcp_comp_sack_nr. Date: Mon, 1 Aug 2022 13:47:04 +0200 Message-Id: <20220801114128.948187739@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220801114128.025615151@linuxfoundation.org> References: <20220801114128.025615151@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit 79f55473bfc8ac51bd6572929a679eeb4da22251 ] While reading sysctl_tcp_comp_sack_nr, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 9c21d2fc41c0 ("tcp: add tcp_comp_sack_nr sysctl") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index f8fa036cfae2..f4e00ff909da 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5303,7 +5303,7 @@ static void __tcp_ack_snd_check(struct sock *sk, int ofo_possible) } if (!tcp_is_sack(tp) || - tp->compressed_ack >= sock_net(sk)->ipv4.sysctl_tcp_comp_sack_nr) + tp->compressed_ack >= READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_comp_sack_nr)) goto send_now; if (tp->compressed_ack_rcv_nxt != tp->rcv_nxt) { -- 2.35.1